[source] kernel: add missing symbol for v4.9

[LEDE Commits]

blogic pushed a commit to source.git, branch master:
https://git.lede-project.org/38f9d08f57e3c3368790a633cd686dfab5acf974

commit 38f9d08f57e3c3368790a633cd686dfab5acf974
Author: John Crispin <john at phrozen.org>
AuthorDate: Wed Feb 15 09:11:11 2017 +0100

    kernel: add missing symbol for v4.9
    
    Signed-off-by: John Crispin <john at phrozen.org>
---
 target/linux/generic/config-4.9 | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/linux/generic/config-4.9 b/target/linux/generic/config-4.9
index 2bf546a..8af65ff 100644
--- a/target/linux/generic/config-4.9
+++ b/target/linux/generic/config-4.9
@@ -4374,6 +4374,7 @@ CONFIG_SYSFS=y
 # CONFIG_SYSFS_DEPRECATED is not set
 # CONFIG_SYSFS_DEPRECATED_V2 is not set
 # CONFIG_SYSFS_SYSCALL is not set
+# CONFIG_SYSCON_REBOOT_MODE is not set
 # CONFIG_SYSTEMPORT is not set
 # CONFIG_SYSTEM_DATA_VERIFICATION is not set
 # CONFIG_SYSTEM_TRUSTED_KEYRING is not set